This also makes two changes to forms: first, forms can
be set to rename the entity, just like views can. This is
enabled for anything using makeModel. Secondly, when switching,
if the new form has a view whose names matches the old form's active
view, it will switch to that same-named view, instead of using
the default view for the form.

So, for example, you'll stay on the "side" view for coins, even when
switching between forms.

Also updates the Blender script.

Also add some tweaks to the process-model script that I managed to lose.

Entities derived from models can now have volumes

This also updates the model-processing script to automatically
insert the model data into the appropriate source file.

These use a new entity-maker.

Firefox won't draw SVGs to a canvas correctly without width/height
attributes (even if a viewBox is present). This commit inserts those
values where needed and removes the Firefox check from the click
detection code, so it works properly (and screenshots are fixed, too).